John Deere 310 A hydraulics quit!

[Tx Jim]

Jerry capobianco
Since the pump has been recently replaced I doubt the drive coupler is the culprit. A high % of pumps are unnecessarily replaced. If sump screen(parts key #9) hasn't been cleaned lately I'd highly recommend it. Filter relief valve(parts key #3) could also not be seating. Have you tried checking stand-by psi?

 

[Jerry capobianco]

No I haven't checked any pressures yet. The machine is in the woods while we were digging a hole it died with the bucket in the hole and it getting cold up so I think we're going to have to wait for spring.we got it all covered up for the winter

 

[Jerry capobianco]

What kind of Gages and fitting would I need to do this pressure test. I could locate them over the winter.

 

[Tx Jim]

You'll need a 3000 & 300 psi gauges available from Surplus Center for under $25.

 

[J_J]

Make up something like these and for a permanent installation, just install the hyd gage in a tee in the IN port of the first valve and mount where you can see it. Then use it for monitoring and troubleshoting.

 

[Jerry capobianco]

I don't think I mentioned that when it was running no hyd and it would not go forward or reverse.
Is there a web site to bring up the hyd system or do I have to buy a manual for a 310B JD. I am greatful for all the info. I'm some what mechanical but not to much on heavy equip but I'm going to give it a shot the machine is in to good a shape
Thanks jerry

 

[Tx Jim]

No forward or reverse indicates trans pump pressure &/or flow because the reverser operates from trans pump output.

 

[Jerry capobianco]

Does that mean that machine has to be split? To get to that pump?

 

[Tx Jim]

1st thing to do is diagnose to determine why trans pump psi isn't getting to reverser BUT yes tractor must be split to R&R trans pump.

 

[Willie B]

It has been a while, memory is somewhat foggy. I sold the manuals with the 410. John deer has a closed center system. If no valve is open asking anything to work oil should not flow at all. pressure builds to a point where pump piston springs aren't strong enough to move pistons back to center in the radial pump. Pistons go "out of stroke" keeping pressure constant. There is no engine disconnect clutch, the "Cam" in the pump continues to rotate, but since pistons don't return to center, they aren't pushed outboard by the cam.

In my case oil leaked past the backhoe valve relieving pressure. There is a priority valve. If pressure falls below a certain level, other functions turn off directing all flow to steering.

Forward uses pump pressure for a clutch reverse uses it for a brake on a gear providing reverse.

Low oil, foamy oil, (the wrong hydraulic fluid), closed center valves leaking oil to the reservois or other pump failures could cause your symptoms. Can you steer?

Those of us who own older yellow Deeres with hydraulic issues won't suffer much shock when we get to ****.